Conventionally, numerical analysis is performed to reproduce phenomena of the heart, which pumps blood throughout the entire body by contractions of the myocardium in response to electrical signals. In general, numerical analysis results are displayed by color coded plots using 3-dimensional computer graphics technology. Distribution of physical values such as stroke work and workrate can be interpreted through cross sectional and isosurface display areas. Techniques are conventionally known that use a computing device to perform numerical simulations related to internal organs such as the stomach, small intestine, large intestine, bladder, etc. in addition to the heart, and use a visualization device to display simulation results to thereby perform visualization of numerical simulations related to the internal organs. For example, refer to Schroeder, W., Martin, K., and Lorensen, B., “The Visualization Toolkit”, 2nd Edition, January 1997, Prentice Hall PTR, pp. 360-362.
Nonetheless, with the conventional techniques above, when the interior of internal organs having a cavity such as the heart, stomach, small intestine, large intestine, and bladder, is to be viewed, a model of the organ has to again be created. Therefore, high-speed rendering of the interior of the organ is difficult. For example, to check blood flow distribution within the heart, after creating a model of the heart having an opening at the location to be observed, rendering has to again be performed, and the direction of blood flow in the heart has to be rendered a high speed, processes that are difficult.